Morphology, Life-History Strategy, and Affinity of the Barrande’s Larva

Barrande’s larva is an early developmental trilobite stage (protaspis) characterized by an effaced, gently vaulted circular exoskeleton about 1 mm in diameter. This early stage was described in 1943 by Robert Růžička. The reinvestigation of all known specimens provides new insights into morphology, ecology, and systematic assignment of this peculiar trilobite stage. The absence of palpebral lobes and eye ridges in Barrande’s larva suggests this protaspid stage belongs to a blind trilobite species. Moreover, the meraspides of a blind conocoryphid trilobite Conocoryphe, which comes from the same strata, fit well the estimated size of the meraspid specimens of Barrande’s larva. It is therefore assumed, that Barrande’s larva is a protaspid stage of Conocoryphe. The large size of Barrande’s larva, its slightly inflated exoskeleton with wide glabella, and low abundance at the type locality indicate lecithotrophic development.